Thanks @Carmelo Scandaliato for the answer.

I'm the original question poster. I gave up at that time because waiting on an update to verify just not ideal. It has been 2 years, now I encounter the same issue. (shoulda just waited lol) Here's my current config without installing gotify-cli:

[emitters]
emit_via = command

[command]
command_format = "curl 'https://<server-address>/message?token=<app-token>' -F 'title=DNF Automatic' -F 'message='{body}''"

stdin_format = "{body}"

PS. I don't know why I posted in python, it's not really a python question lol.